FUNCTIONAL STUDIES OF OSTEOBLASTS

成骨细胞的功能研究

• 批准号: 2733731
• 负责人: Carol V Gay
• 金额: $ 27.63万
• 依托单位: PENNSYLVANIA STATE UNIVERSITY, THE
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-04-01 至 2001-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2733731
• 关键词: 1,25 dihydroxycholecalciferol; antibody; calcium; calcium flux; calcium transporting ATPase; cell membrane; cellular polarity; chickens; confocal scanning microscopy; dexamethasone; fluorescent dye /probe; glucocorticoids; immunocytochemistry; membrane transport proteins; normal ossification; osteoblasts; osteocytes; protein sequence; sodium; sodium potassium exchanging ATPase; tissue /cell culture; vesicle /vacuole

DESCRIPTION (Adapted from applicant's Abstract): The long term objective of this research program is to understand bone cell function in vivo. The goal of the studies delineated in this application is to identify and characterize the means by which calcium ions (Ca++) are delivered to-sites of mineralization. Previously, the Principal Investigator has shown that Ca-ATPase is present in substantial amounts in osteoblast plasma membrane, but is oriented such that it is not likely to focus Ca++ secretion toward bone surfaces. Consequently, the Principal Investigator will examine mechanisms that drive Ca++ in large quantities out of cells, focusing Ca++ into sites of mineralization. Osteoblasts covering bone surfaces can be considered as a continuous layer, a mesothelium, that has the capacity to translocate ions vectorially. The specific aims are: 1) to evaluate polarity development, and retention in cultured osteoblasts as compared with freshly isolated osteoblasts and intact tissue; 2) to develop a means of visualizing the physical location of proteins believed to focus Ca++ into sites of mineralization using immunocytochemistry;- 3) to monitor Ca++ efflux from cells (freshly isolated and cultured) using a newly developed fluorescent probe that can trap Ca++ as it emerges from the cell; 4) to run the process in reverse to verify results obtained in Specific Aim 3; 5) to monitor rates of Ca++ efflux in isolated plasma membrane vesicles; and 6) to determine sites and possible regulatory mechanisms of Na/K-ATPase, an enzyme responsible for driving Ca++ fluxes in exchange for Na+. Understanding the mechanisms by which normal osteoblasts provide calcium to extracellular bone provides a basis for comparing bone cell function in the diseased skeleton. In addition, the new knowledge derived from these studies may assist in the eventual design of new therapeutics to combat skeletal diseases.

描述（改编自申请人摘要）：长期目标